Method of oxidizing paraffin wax and the product thereof



Mad May 23, 1933 UNITED STATES PATENT; forrlca DENIM GALLSWOITEY, OI BAYONNE, NEW JERSEY, ASSIGNOR, BY IESNE ASSIGN- mflfl, T m 'rms OOKPANY, 01' NEW YORK, N. Y, A CORPORATION 01 DELA- mnon or 'onmzmo rmrrm wax inn ran raonuc-r mammot- This invention, a continuation in part of my copending apphcation filed September 24, 1924, Serial No. 739,527, relates to the oxidation of h drocarbons and. more partlcularly 5 to the oxldation of paraflin wax.

The primary efiorts of prior investigators dealing with the oxidation of \parafiin wax have been to roduce acids of high molecular weight resembling the natural fatty aclds and i which might be used to replace the latter in the arts, particularly soap making. lily the .use of high temperatures and rapid 1n ]ect1on of air or oxy en, large amounts of acid may be formed. he purpose of my invention, however, is to produce material hav1n as low an acid value as possible while obtaining a large amount of saponifiable bodies; an additlonal .purpose is to obtain an oxidized wax which is soluble in hydrocarbon oils, especially lubricating oils at temperatures ordmarily encountered in marketing or use. p

The saponifiable bodies or esters obtained during the oxidation of paraflin wax are beneficial in increasing the lubricating properties of mineral oils.

Since lubricatin oils, particularl motor oils, must have good transparency, it as been m aim to make such oxidized wax completely so uble in lubricating oil so that no clouding would occur even at low temperatures. Parafiin wax by itself is not appreciably soluble in lubricating oils at low temperatures and it is therefore apparent that the oxidized wax used for compounding with oils must not contain any excessive amount of unchanged wax.

It has been discovered, however, from extended observation that the presence of oxidized wax increases to a marked degree the solubility of unoxidized wax in the oil; thus it becomes unnecessary in most instances to oxidize the wax excessively and in some cases even as much as of unchanged wax is entirely permissible. On the other hand, it is especially desirable to avoid energetic oxida- 45 tion at higher temperatures or oxidation at moderate temperatures for an extended peri- 0d of time. Such treatment results in the formation of a certain amount of material which is partially insoluble in lubricating oils. Ifa portion of such over-oxidized wax Application fled n n as, 1927. Serial n. 1mm. 1

is compounded with lubricatin oil and allowed to stand, a red gummy eposit forms at the bottom of the vessel in which it is stored; this red gum is likely to .deposit on moving parts whlch may be subjected to lubrication with oil containing this gum and may cause trouble in their operation. The

present method of oxidation has, therefore,

been developed to give an oxidation product which is soluble in lubricating oils at average atmospheric temperatures of this locality, particularly at temperatures above the cloud point or pour point of the original oils, which is free from gum, and which contains a large proportion of saponifiable bodies. I

In carrying. out the oxidation a charge of paraflin wax, for example crude scale wax aving 'a gravity of between 48 and 50 A. P. I. at 130 F., is placed in an enameled or aluminum vessel which is preferably jack- 'eted or otherwise fitted to permit heating or cooling of the contents. The vessel should also be fitted with an air distributor, preferably located near the bottom, through which air may be introduced in fine streams to promote intimate contact of the air with the oxidizing mass. If the vessel is well insulated, the heat developed by the oxidation will be suflicient to maintain the charge at the proper temperature once it hasbeen brought to that temperature by outside means such as a steam coil. In fact it has been found that it is occasionally desirable to supply external cooling means such as cooled oil to prevent an increase in the temperature beyond that contemplated. The charge of wax may be heated to a temperature of between 260 to 330 F. and air may be introduced in suflicient quantity to maintain the desired temperature.

vThe mention of this temperature range does not preclude the use of other temperatures in the oxidation, but it is to be noted that excessive temperatures tend to the formation of red gum which is undesirable in the finished product and such temperatures should, therefore, be avoided. In the light of present knowledge the most satisfactory temperatures for the oxidation are about 315 to 320 F.; although satisfactory I material has been made commercially at 100 temperatures as high as 335 F., it is preferred to operate at the lower temperatures.

The oxidation is allowed to proceed until a small sample of the batch indicates a gravity preferably of about 34 A. P. I. at 130 F., although gravities of 33 to 35 A. P. I. are acceptable. By thu observing the gravity of the oxidizing kproduct the quality maybe closely controlle es ecially as to its freedom from red gum. bservations made over an extended period of time indicate that material falling within this range of gravities is free from gummy products and is entirely soluble in lubricating oils.

A test from which it may be concluded that the oxidized wax is free from gum consists in preparing a 10% solution of the oxidized wax in a light distillate, preferably 86 B. gasoline, and allowing the solution to stand until clear. The absence of a precipitate at the bottom of the vessel containing the solution is an indication that the oxidized majectionable, this may be removed from the- '55 terial is free from gum.

As an illustrative example of the invention, the following operatmg data may be given: A charge of about 2300 pounds of crude scale wax was placed in an enameled vessel, and after preliminary heating air was introduced to maintain a temperature of about 320 F. .The oxidation was continued for a period of about 16 hours or until the batch of oxidizing wax indicated a avity of about 34 A. P. I. at 130 F. The ished material was .found to be of excellent color and showed no traces of gummy material when mixed with 86 B. gasoline to form a 10% solution. The oxidized wax had an acid number of about 26 and a total saponification value of about 93, giving a ratio of neutralv proportion wax rebe obmass of oxidized material by the well known process of sweating, similar to that commonly practiced in the removal of oil from crude paraflin wax. In this manner the higher melting portions of the oxidized mass may be eliminated from the lower melting portions and the former subjected to further oxidation treatment if desired. If this supplemental treatment is practised, it is possible to discontinue oxidation sooner than otherwise would be possible and yet obtain oxidized material having a high ratio of neutral saponification number to acid number and also having a complete solubility in pale lubricating oils at ordinary temperatures, such as 20 F.100 F.

This supplemental sweating treatment may be of considerable importance in the preparation of materials suitable for soap making inasmuch as it enables the'production of exceptionally light colored materials of any desired melting point. It has been customary in the prior art, in carryin on the oxidation of the paratlin wax, to efiect as complete conversion as possible into acids and other saponifiable matter when seeking the reparation of soap making materials. In ollowing such a procedure, however, as pointed out above, the mass of oxidizing material becomes progressively darker and contains more and more of gummy products and other materials unsuited to saponification.

If, on the other hand. the oxidation is discontinued before these detrimental substances form, the lower meltin materials may be segregated from the hi er melting portions by sweating and the ormer being of good color and quality chemically, may be used inv-soap makin and the like while the higher melting portlons may be subjected to further oxidation.

While I have thus specifically described my invention, numerous modifications thereof; will suggest themselves to those skilled in the'art and it is therefore to be limited only A as indicated in the appended claims.

What I claim is:

1. A composition of matter consisting of a paraffin wax which has been oxidized in such a manner as to contain only a minor pro ortion of unoxidized wax and substantial y no gummy products and to be substantially com letely soluble to the extent of about 3% 1n lubricating oils over the range of normal atmospheric temperatures of 20 F. F., said composition having a grav ity of about 33 to about 35 A. P. I. at 130 F.

' 2. A composition of matter consisting of a parafiin wax which has been oxidized in I such a manner as to contain only a minor pro ortion of unoxidized wax and substantial y no gummy products and to be substantially completely soluble to the extent of at least 3% in 300 seconds viscosity (Saybolt) lubricating oil at temperatures above the cloud point of said oil, said composition having a gravity of about 33 to about 35 A. P. I. at 130 F.

3. A composition of matter consisting of an oxidized paraifin wax, having an A. I. gravity of about 33-35 at 130 F., formed y oxidizing parafiin wax of about 50 A. P. I. at 130 F., in such a manner as to contain a major proportion of saponifiable constituents, to have a ratio of saponification value -to acid value of about 3 to 1, and to be substantially completely soluble to the extent of at least 2% in lubricating oil at temperatures in excess of 20 F. 5 4. The method of oxidizing paraflin wax which consists in iblowing the wax with air,

while heated to a tem erature of about 300 F., for a suflicient perlod of time to produce an oxidized mass which dissolves to the extent of about 10% in gasoline without deposition of gummy products and completely dissolves to the extentof at least 3% in lubricatingoil at temperatures above the pour point 0 said oil, and then discontinuing 1 oxidation.

5. The method of oxidizing paraflin wax which consists in blowing the wax with air, while heated to a temperature of about 300 F., for such a period of time that-the remaining oxidized mass contains relativelylittle unchanged wax and completely dissolves in substantial amount in lubricating oils at temperatures in excess of 0 .F.,- and for a period of time less than that required to produce an over-oxidized mass containing gummy products which recipitate in a 90% gaso-' line solution, and then discontinuing oxidation.

6. The method of oxidizing paraflin wax having a gravity of the order of A. P. I. at 130 F. which comprises exposing the wax F., then discontinuing oxidation, and subjecting. the oxidized mass to a sweating operation to separate the higher melting portions from the lower melting portions.

10. The method of oxidizing paraflin wax which comprises exposing the wax to the action of an oxidizing gas while under the influence of heat for such a period of time that the remainin oxidized mass shows a ratio of saponification value to acid. value of.

over 2% to 1 and contains onl a minor proportion of unoxidized wax an substantlally no gummy products and is completely soluble to the extent of at least 2% in lubricating oil at temperatures above the cloud point of said oil, and then discontinuing oxidation, said oxidized mass hlzgying a gravity of about 33 to about 35 A. I at 130 F.

In witness whereof I have hereunto set my handthis 21st da of March 1927.

BENJ A IN GALLSWORTHY.

to the action of an oxidizing gas while under the influence of heat, and discontinuing the oxidation when the gravit of the remain- 5 ing oxidized mass has attained about 34 A. P. I. at 130 F.,whereb a mass free from gummy products insolubl e in hydrocarbon oils is formed.

7. The method of oxidizing parafiin wax 40 having a gravit of the order of 50 A. P. I. at 130 F. whic comprises blowing the Wax with air while heated to a temperature of 260 F. to 335 F., untilthe remaining oxidized mass attains about 34 4 i A. P. I. at 130 F., and then discontinuing the oxidation, whereb a mass free from 'gummy products inso uble in hydrocarbon oils is formed.

' a 8. The method of oxidizing araflin wax 50 having a gravity of the orderv 0 50 A. P. I. at 130 F. which comprises exposing the wax. to the action of an oxidizing gas while under avity of the the influence of heat, and discontinuin the agravity of about 33 to 35 A. P. I. at 130 

